# average velocity

• Sep 16th 2008, 10:28 AM
cwarzecha
average velocity
Consider a car whose position, s, is given by the table

t (sec) 0 0.2 0.4 0.6 0.8 1
s (ft) 0 0.5 1.7 3.8 6.5 9.6

Find the average velocity over the interval 0<=t<=0.2

Estimate the velocity at t=0.2
• Sep 16th 2008, 10:43 AM
icemanfan
Velocity is calculated as distance over time, so the average velocity over an interval will be the total distance traveled in that interval divided by the total time taken to travel that distance.
• Sep 16th 2008, 10:53 AM
cwarzecha
ok that makes sense but how do you estimate the time at 0.2?
• Sep 16th 2008, 11:00 AM
topsquark
Quote:

Originally Posted by cwarzecha
Consider a car whose position, s, is given by the table

t (sec) 0 0.2 0.4 0.6 0.8 1
s (ft) 0 0.5 1.7 3.8 6.5 9.6

Estimate the velocity at t=0.2

Sketch a graph of the data then sketch a smooth curve connecting those points. The instantaneous speed at 0.2 s will be the slope of the line that is tangent to your curve at 0.2 s.

-Dan
• Sep 16th 2008, 11:09 AM
cwarzecha
i sketched a graph and i got a line. is it the slope of that line?
• Sep 17th 2008, 08:24 AM
topsquark
Quote:

Originally Posted by cwarzecha
i sketched a graph and i got a line. is it the slope of that line?

Yes, the slope of the line tangent to a given line is the slope of the given line.

Ie. The slope of the tangent to y = mx + b is m.

-Dan
• Sep 17th 2008, 03:14 PM
cwarzecha
Thanks